Commit Graph

571 Commits

Author SHA1 Message Date
Teresa Johnson 89aab30a42 [ThinLTO] Rename HasSection to NoRename (NFC)
Summary:
This is in preparation for a change to utilize this flag for symbols
referenced/defined in either inline or module level assembly.

Reviewers: mehdi_amini

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D26048

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285376 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-28 02:24:59 +00:00
Simon Pilgrim 2c99feb9ec Fix spelling mistake in comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284714 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-20 10:42:14 +00:00
Simon Pilgrim 67c3574910 Fix MSVC bool -> uint64_t promotion warning
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284713 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-20 10:37:58 +00:00
Victor Leschuk e69c459a6e DebugInfo: preparation to implement DW_AT_alignment
- Add alignment attribute to DIVariable family
 - Modify bitcode format to match new DIVariable representation
 - Update tests to match these changes (also add bitcode upgrade test)
 - Expect that frontend passes non-zero align value only when it is not default
   (was forcibly aligned by alignas()/_Alignas()/__atribute__(aligned())

Differential Revision: https://reviews.llvm.org/D25073


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284678 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-20 00:13:12 +00:00
Piotr Padlewski fdf7354745 [thinlto] Basic thinlto fdo heuristic
Summary:
This patch improves thinlto importer
by importing 3x larger functions that are called from hot block.

I compared performance with the trunk on spec, and there
were about 2% on povray and 3.33% on milc. These results seems
to be consistant and match the results Teresa got with her simple
heuristic. Some benchmarks got slower but I think they are just
noisy (mcf, xalancbmki, omnetpp)- running the benchmarks again with
more iterations to confirm. Geomean of all benchmarks including the noisy ones
were about +0.02%.

I see much better improvement on google branch with Easwaran patch
for pgo callsite inlining (the inliner actually inline those big functions)
Over all I see +0.5% improvement, and I get +8.65% on povray.
So I guess we will see much bigger change when Easwaran patch will land
(it depends on new pass manager), but it is still worth putting this to trunk
before it.

Implementation details changes:
- Removed CallsiteCount.
- ProfileCount got replaced by Hotness
- hot-import-multiplier is set to 3.0 for now,
didn't have time to tune it up, but I see that we get most of the interesting
functions with 3, so there is no much performance difference with higher, and
binary size doesn't grow as much as with 10.0.

Reviewers: eraman, mehdi_amini, tejohnson

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D24638

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282437 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-26 20:37:32 +00:00
Teresa Johnson 7e15c9e40f [ThinLTO] Always emit a summary when compiling in ThinLTO mode
Summary:
Emit an empty summary section, instead of no summary section, when
there are no global variables in the index. This ensures that LTO
will treat these files as ThinLTO inputs, instead of as regular
LTO inputs.

In addition to not being what the user likely intended when
compiling with -flto=thin, the current behavior is problematic for
distributed build systems that expect to get ThinLTO index and imports
files back for each input compiled with -flto=thin. Combining into
a single regular LTO module also reduces the backend parallelism.
And in the case where the index was suppressed due to uses in
inline assembly, combining into a single LTO module could provoke
renaming of duplicates that we were trying to prevent by suppressing
the index.

This change required a couple of fixes to handle the empty summary
section.

Reviewers: mehdi_amini

Subscribers: mehdi_amini, llvm-commits, pcc

Differential Revision: https://reviews.llvm.org/D24779

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282037 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-20 23:07:17 +00:00
Mehdi Amini a2d3e0354c BitcodeWriter: fix emission of invoke when calling a var-arg function with operand bundles
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281940 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-19 21:27:04 +00:00
Mehdi Amini d1e3c5aaec Don't create a SymbolTable in Function when the LLVMContext discards value names (NFC)
The ValueSymbolTable is used to detect name conflict and rename
instructions automatically. This is not needed when the value
names are automatically discarded by the LLVMContext.
No functional change intended, just saving a little bit of memory.

This is a recommit of r281806 after fixing the accessor to return
a pointer instead of a reference and updating all the call-sites.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281813 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-17 06:00:02 +00:00
Peter Collingbourne 5420de3f15 DebugInfo: New metadata representation for global variables.
This patch reverses the edge from DIGlobalVariable to GlobalVariable.
This will allow us to more easily preserve debug info metadata when
manipulating global variables.

Fixes PR30362. A program for upgrading test cases is attached to that
bug.

Differential Revision: http://reviews.llvm.org/D20147

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281284 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-13 01:12:59 +00:00
David Blaikie bf471b7adc DebugInfo: Add flag to CU to disable emission of inline debug info into the skeleton CU
In cases where .dwo/.dwp files are guaranteed to be available, skipping
the extra online (in the .o file) inline info can save a substantial
amount of space - see the original r221306 for more details there.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279650 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-24 18:29:49 +00:00
Mehdi Amini 855d81dc03 Constify some path in the bitcode writer (NFC)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279211 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-19 06:06:18 +00:00
Piotr Padlewski fb2a7f990d Don't import variadic functions
Summary:
This patch adds IsVariadicFunction bit to summary in order
to not import variadic functions. Inliner doesn't inline
variadic functions because it is hard to reason about it.

This one small fix improves Importer by about 16%
(going from 86% to 100% of imported functions that are
inlined anywhere)
on some spec benchmarks like 'int' and others.

Reviewers: eraman, mehdi_amini, tejohnson

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23339

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278432 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-11 22:13:57 +00:00
Teresa Johnson 5e89a802f2 [ThinLTO] Address review comments from PGO indirect call promotion (NFC)
Address a couple of post-commit review comments from r275707.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275867 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-18 18:31:50 +00:00
Teresa Johnson e2f34269f3 [ThinLTO] Perform profile-guided indirect call promotion
Summary:
To enable profile-guided indirect call promotion in ThinLTO mode, we
simply add call graph edges for each profitable target from the profile
to the summaries, then the summary-guided importing will consider the
callee for importing as usual.

Also we need to enable the indirect call promotion pass creation in the
PassManagerBuilder when PerformThinLTO=true (we are in the ThinLTO
backend), so that the newly imported functions are considered for
promotion in the backends.

The IC promotion profiles refer to callees by GUID, which required
adding GUIDs to the per-module VST in bitcode (and assigning them
valueIds similar to how they are assigned valueIds in the combined
index).

Reviewers: mehdi_amini, xur

Subscribers: mehdi_amini, davidxl, llvm-commits

Differential Revision: http://reviews.llvm.org/D21932

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275707 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-17 14:47:01 +00:00
Nicolai Haehnle b07f540456 Add writeonly IR attribute
Summary:
This complements the earlier addition of IntrWriteMem and IntrWriteArgMem
LLVM intrinsic properties, see D18291.

Also start using the attribute for memset, memcpy, and memmove intrinsics,
and remove their special-casing in BasicAliasAnalysis.

Reviewers: reames, joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D18714

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274485 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-04 08:01:29 +00:00
Reid Kleckner bd79db219f [codeview] Add DISubprogram::ThisAdjustment
Summary:
This represents the adjustment applied to the implicit 'this' parameter
in the prologue of a virtual method in the MS C++ ABI. The adjustment is
always zero unless multiple inheritance is involved.

This increases the size of DISubprogram by 8 bytes, unfortunately. The
adjustment really is a signed 32-bit integer. If this size increase is
too much, we could probably win it back by splitting out a subclass with
info specific to virtual methods (virtuality, vindex, thisadjustment,
containingType).

Reviewers: aprantl, dexonsmith

Subscribers: aaboud, amccarth, llvm-commits

Differential Revision: http://reviews.llvm.org/D21614

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274325 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-01 02:41:21 +00:00
Peter Collingbourne 1d084dfa7b BitcodeWriter: Remove redundant (and incorrect) check for whether to emit module summary.
The function name Module::empty() is slightly misleading in that it
only tests for the presence of functions in the module. However we
still want to emit the module summary if the module contains only
global variables or aliases. The presence of such entities can be
determined simply by checking the summary directly, as we are doing
below.

Differential Revision: http://reviews.llvm.org/D21669

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273638 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-24 01:58:02 +00:00
Peter Collingbourne 99e2e27b37 IR: Allow metadata attachments on declarations, and fix lazy loaded metadata issue with globals.
This change is motivated by an upcoming change to the metadata representation
used for CFI. The indirect function call checker needs type information for
external function declarations in order to correctly generate jump table
entries for such declarations. We currently associate such type information
with declarations using a global metadata node, but I plan [1] to move all
such metadata to global object attachments.

In bitcode, metadata attachments for function declarations appear in the
global metadata block. This seems reasonable to me because I expect metadata
attachments on declarations to be uncommon. In the long term I'd also expect
this to be the case for CFI, because we'd want to use some specialized bitcode
format for this metadata that could be read as part of the ThinLTO thin-link
phase, which would mean that it would not appear in the global metadata block.

To solve the lazy loaded metadata issue I was seeing with D20147, I use the
same bitcode representation for metadata attachments for global variables as I
do for function declarations. Since there's a use case for metadata attachments
in the global metadata block, we might as well use that representation for
global variables as well, at least until we have a mechanism for lazy loading
global variables.

In the assembly format, the metadata attachments appear after the "declare"
keyword in order to avoid a parsing ambiguity.

[1] http://lists.llvm.org/pipermail/llvm-dev/2016-June/100462.html

Differential Revision: http://reviews.llvm.org/D21052

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273336 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-21 23:42:48 +00:00
Peter Collingbourne 63b34cdf34 IR: Introduce local_unnamed_addr attribute.
If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.

This attribute is intended to be used by the code generator and LTO to allow
the linker to decide whether the global needs to be in the symbol table. It is
possible to exclude a global from the symbol table if three things are true:
- This attribute is present on every instance of the global (which means that
  the normal rule that the global must have a unique address can be broken without
  being observable by the program by performing comparisons against the global's
  address)
- The global has linkonce_odr linkage (which means that each linkage unit must have
  its own copy of the global if it requires one, and the copy in each linkage unit
  must be the same)
- It is a constant or a function (which means that the program cannot observe that
  the unique-address rule has been broken by writing to the global)

Although this attribute could in principle be computed from the module
contents, LTO clients (i.e. linkers) will normally need to be able to compute
this property as part of symbol resolution, and it would be inefficient to
materialize every module just to compute it.

See:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160509/356401.html
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160516/356738.html
for earlier discussion.

Part of the fix for PR27553.

Differential Revision: http://reviews.llvm.org/D20348

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272709 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-14 21:01:22 +00:00
Reid Kleckner 3d3aca2d97 [DebugInfo] Add calling convention support for DWARF and CodeView
Summary:
Now DISubroutineType has a 'cc' field which should be a DW_CC_ enum.  If
it is present and non-zero, the backend will emit it as a
DW_AT_calling_convention attribute. On the CodeView side, we translate
it to the appropriate enum for the LF_PROCEDURE record.

I added a new LLVM vendor specific enum to the list of DWARF calling
conventions. DWARF does not appear to attempt to standardize these, so I
assume it's OK to do this until we coordinate with GCC on how to emit
vectorcall convention functions.

Reviewers: dexonsmith, majnemer, aaboud, amccarth

Subscribers: mehdi_amini, llvm-commits

Differential Revision: http://reviews.llvm.org/D21114

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272197 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-08 20:34:29 +00:00
Peter Collingbourne 6aef9f9248 Add support for metadata attachments for global variables.
This patch adds an IR, assembly and bitcode representation for metadata
attachments for globals. Future patches will port existing features to use
these new attachments.

Differential Revision: http://reviews.llvm.org/D20074

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271348 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-31 23:01:54 +00:00
Mehdi Amini 7b24ae662c Avoid temporary vector for sorting in BitcodeWriter
As suggested by Duncan, fixup for r269634 and r269635

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269715 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-16 22:47:15 +00:00
Mehdi Amini 4087d8ab8f ThinLTO: fix non-determinism in bitcode writing
Calls are initialized from a DenseMap. We can sort them using the
value id to recover some determinism during serialization.

From: mehdi_amini <mehdi_amini@91177308-0d34-0410-b5e6-96231b3b80d8>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269638 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-16 09:04:55 +00:00
Mehdi Amini 78132b5695 Revert "ThinLTO: fix non-determinism in bitcode writing"
This reverts commit r269634, bots are broken.

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269637 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-16 09:04:50 +00:00
Mehdi Amini 5975742a11 ThinLTO: fix another non-determinism in bitcode writing
GlobalVars Refs are initialized from a DenseSet. We can sort them
using the value id to recover some determinism during serialization.

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269635 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-16 08:50:27 +00:00